Païsius or Païsios may refer to:
- Pishoy or Bishoy, 320-417 AD, an Egyptian desert father and Christian saint; Παΐσιος Paisios is the Greek form and Paisius the Latin form
- Patriarch Paisius I of Jerusalem, 17th century
- Patriarch Paisius I of Constantinople
- Patriarch Paisius II of Constantinople, 18th century
- Patriarch Paisius of Alexandria, patriarch from 1657 to 1678
- Paisius Ligarides
- Saint Paisius of Hilendar (Paisiy Hilendarski), an 18th century Bulgarian National Revival figure
- Paisius Velichkovsky, the founder of modern Eastern Orthodox staretsdom
- Paisios (Eznepidis), also known as Elder Paisios of Mount Athos, a 20th-century monk